The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_linker.c

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    1 /*-
    2  * Copyright (c) 1997-2000 Doug Rabson
    3  * All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  *
   14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   24  * SUCH DAMAGE.
   25  */
   26 
   27 #include <sys/cdefs.h>
   28 __FBSDID("$FreeBSD: releng/8.1/sys/kern/kern_linker.c 199583 2009-11-20 15:27:52Z jhb $");
   29 
   30 #include "opt_ddb.h"
   31 #include "opt_hwpmc_hooks.h"
   32 
   33 #include <sys/param.h>
   34 #include <sys/kernel.h>
   35 #include <sys/systm.h>
   36 #include <sys/malloc.h>
   37 #include <sys/sysproto.h>
   38 #include <sys/sysent.h>
   39 #include <sys/priv.h>
   40 #include <sys/proc.h>
   41 #include <sys/lock.h>
   42 #include <sys/mutex.h>
   43 #include <sys/sx.h>
   44 #include <sys/module.h>
   45 #include <sys/mount.h>
   46 #include <sys/linker.h>
   47 #include <sys/fcntl.h>
   48 #include <sys/jail.h>
   49 #include <sys/libkern.h>
   50 #include <sys/namei.h>
   51 #include <sys/vnode.h>
   52 #include <sys/syscallsubr.h>
   53 #include <sys/sysctl.h>
   54 
   55 #include <net/vnet.h>
   56 
   57 #include <security/mac/mac_framework.h>
   58 
   59 #include "linker_if.h"
   60 
   61 #ifdef HWPMC_HOOKS
   62 #include <sys/pmckern.h>
   63 #endif
   64 
   65 #ifdef KLD_DEBUG
   66 int kld_debug = 0;
   67 #endif
   68 
   69 #define KLD_LOCK()              sx_xlock(&kld_sx)
   70 #define KLD_UNLOCK()            sx_xunlock(&kld_sx)
   71 #define KLD_LOCKED()            sx_xlocked(&kld_sx)
   72 #define KLD_LOCK_ASSERT() do {                                          \
   73         if (!cold)                                                      \
   74                 sx_assert(&kld_sx, SX_XLOCKED);                         \
   75 } while (0)
   76 
   77 /*
   78  * static char *linker_search_path(const char *name, struct mod_depend
   79  * *verinfo);
   80  */
   81 static const char       *linker_basename(const char *path);
   82 
   83 /*
   84  * Find a currently loaded file given its filename.
   85  */
   86 static linker_file_t linker_find_file_by_name(const char* _filename);
   87 
   88 /*
   89  * Find a currently loaded file given its file id.
   90  */
   91 static linker_file_t linker_find_file_by_id(int _fileid);
   92 
   93 /* Metadata from the static kernel */
   94 SET_DECLARE(modmetadata_set, struct mod_metadata);
   95 
   96 MALLOC_DEFINE(M_LINKER, "linker", "kernel linker");
   97 
   98 linker_file_t linker_kernel_file;
   99 
  100 static struct sx kld_sx;        /* kernel linker lock */
  101 
  102 /*
  103  * Load counter used by clients to determine if a linker file has been
  104  * re-loaded. This counter is incremented for each file load.
  105  */
  106 static int loadcnt;
  107 
  108 static linker_class_list_t classes;
  109 static linker_file_list_t linker_files;
  110 static int next_file_id = 1;
  111 static int linker_no_more_classes = 0;
  112 
  113 #define LINKER_GET_NEXT_FILE_ID(a) do {                                 \
  114         linker_file_t lftmp;                                            \
  115                                                                         \
  116         KLD_LOCK_ASSERT();                                              \
  117 retry:                                                                  \
  118         TAILQ_FOREACH(lftmp, &linker_files, link) {                     \
  119                 if (next_file_id == lftmp->id) {                        \
  120                         next_file_id++;                                 \
  121                         goto retry;                                     \
  122                 }                                                       \
  123         }                                                               \
  124         (a) = next_file_id;                                             \
  125 } while(0)
  126 
  127 
  128 /* XXX wrong name; we're looking at version provision tags here, not modules */
  129 typedef TAILQ_HEAD(, modlist) modlisthead_t;
  130 struct modlist {
  131         TAILQ_ENTRY(modlist) link;      /* chain together all modules */
  132         linker_file_t   container;
  133         const char      *name;
  134         int             version;
  135 };
  136 typedef struct modlist *modlist_t;
  137 static modlisthead_t found_modules;
  138 
  139 static int      linker_file_add_dependency(linker_file_t file,
  140                     linker_file_t dep);
  141 static caddr_t  linker_file_lookup_symbol_internal(linker_file_t file,
  142                     const char* name, int deps);
  143 static int      linker_load_module(const char *kldname,
  144                     const char *modname, struct linker_file *parent,
  145                     struct mod_depend *verinfo, struct linker_file **lfpp);
  146 static modlist_t modlist_lookup2(const char *name, struct mod_depend *verinfo);
  147 
  148 static char *
  149 linker_strdup(const char *str)
  150 {
  151         char *result;
  152 
  153         if ((result = malloc((strlen(str) + 1), M_LINKER, M_WAITOK)) != NULL)
  154                 strcpy(result, str);
  155         return (result);
  156 }
  157 
  158 static void
  159 linker_init(void *arg)
  160 {
  161 
  162         sx_init(&kld_sx, "kernel linker");
  163         TAILQ_INIT(&classes);
  164         TAILQ_INIT(&linker_files);
  165 }
  166 
  167 SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0);
  168 
  169 static void
  170 linker_stop_class_add(void *arg)
  171 {
  172 
  173         linker_no_more_classes = 1;
  174 }
  175 
  176 SYSINIT(linker_class, SI_SUB_KLD, SI_ORDER_ANY, linker_stop_class_add, NULL);
  177 
  178 int
  179 linker_add_class(linker_class_t lc)
  180 {
  181 
  182         /*
  183          * We disallow any class registration past SI_ORDER_ANY
  184          * of SI_SUB_KLD.  We bump the reference count to keep the
  185          * ops from being freed.
  186          */
  187         if (linker_no_more_classes == 1)
  188                 return (EPERM);
  189         kobj_class_compile((kobj_class_t) lc);
  190         ((kobj_class_t)lc)->refs++;     /* XXX: kobj_mtx */
  191         TAILQ_INSERT_TAIL(&classes, lc, link);
  192         return (0);
  193 }
  194 
  195 static void
  196 linker_file_sysinit(linker_file_t lf)
  197 {
  198         struct sysinit **start, **stop, **sipp, **xipp, *save;
  199 
  200         KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n",
  201             lf->filename));
  202 
  203         if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0)
  204                 return;
  205         /*
  206          * Perform a bubble sort of the system initialization objects by
  207          * their subsystem (primary key) and order (secondary key).
  208          *
  209          * Since some things care about execution order, this is the operation
  210          * which ensures continued function.
  211          */
  212         for (sipp = start; sipp < stop; sipp++) {
  213                 for (xipp = sipp + 1; xipp < stop; xipp++) {
  214                         if ((*sipp)->subsystem < (*xipp)->subsystem ||
  215                             ((*sipp)->subsystem == (*xipp)->subsystem &&
  216                             (*sipp)->order <= (*xipp)->order))
  217                                 continue;       /* skip */
  218                         save = *sipp;
  219                         *sipp = *xipp;
  220                         *xipp = save;
  221                 }
  222         }
  223 
  224         /*
  225          * Traverse the (now) ordered list of system initialization tasks.
  226          * Perform each task, and continue on to the next task.
  227          */
  228         mtx_lock(&Giant);
  229         for (sipp = start; sipp < stop; sipp++) {
  230                 if ((*sipp)->subsystem == SI_SUB_DUMMY)
  231                         continue;       /* skip dummy task(s) */
  232 
  233                 /* Call function */
  234                 (*((*sipp)->func)) ((*sipp)->udata);
  235         }
  236         mtx_unlock(&Giant);
  237 }
  238 
  239 static void
  240 linker_file_sysuninit(linker_file_t lf)
  241 {
  242         struct sysinit **start, **stop, **sipp, **xipp, *save;
  243 
  244         KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n",
  245             lf->filename));
  246 
  247         if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop,
  248             NULL) != 0)
  249                 return;
  250 
  251         /*
  252          * Perform a reverse bubble sort of the system initialization objects
  253          * by their subsystem (primary key) and order (secondary key).
  254          *
  255          * Since some things care about execution order, this is the operation
  256          * which ensures continued function.
  257          */
  258         for (sipp = start; sipp < stop; sipp++) {
  259                 for (xipp = sipp + 1; xipp < stop; xipp++) {
  260                         if ((*sipp)->subsystem > (*xipp)->subsystem ||
  261                             ((*sipp)->subsystem == (*xipp)->subsystem &&
  262                             (*sipp)->order >= (*xipp)->order))
  263                                 continue;       /* skip */
  264                         save = *sipp;
  265                         *sipp = *xipp;
  266                         *xipp = save;
  267                 }
  268         }
  269 
  270         /*
  271          * Traverse the (now) ordered list of system initialization tasks.
  272          * Perform each task, and continue on to the next task.
  273          */
  274         mtx_lock(&Giant);
  275         for (sipp = start; sipp < stop; sipp++) {
  276                 if ((*sipp)->subsystem == SI_SUB_DUMMY)
  277                         continue;       /* skip dummy task(s) */
  278 
  279                 /* Call function */
  280                 (*((*sipp)->func)) ((*sipp)->udata);
  281         }
  282         mtx_unlock(&Giant);
  283 }
  284 
  285 static void
  286 linker_file_register_sysctls(linker_file_t lf)
  287 {
  288         struct sysctl_oid **start, **stop, **oidp;
  289 
  290         KLD_DPF(FILE,
  291             ("linker_file_register_sysctls: registering SYSCTLs for %s\n",
  292             lf->filename));
  293 
  294         if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
  295                 return;
  296 
  297         sysctl_lock();
  298         for (oidp = start; oidp < stop; oidp++)
  299                 sysctl_register_oid(*oidp);
  300         sysctl_unlock();
  301 }
  302 
  303 static void
  304 linker_file_unregister_sysctls(linker_file_t lf)
  305 {
  306         struct sysctl_oid **start, **stop, **oidp;
  307 
  308         KLD_DPF(FILE, ("linker_file_unregister_sysctls: registering SYSCTLs"
  309             " for %s\n", lf->filename));
  310 
  311         if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
  312                 return;
  313 
  314         sysctl_lock();
  315         for (oidp = start; oidp < stop; oidp++)
  316                 sysctl_unregister_oid(*oidp);
  317         sysctl_unlock();
  318 }
  319 
  320 static int
  321 linker_file_register_modules(linker_file_t lf)
  322 {
  323         struct mod_metadata **start, **stop, **mdp;
  324         const moduledata_t *moddata;
  325         int first_error, error;
  326 
  327         KLD_DPF(FILE, ("linker_file_register_modules: registering modules"
  328             " in %s\n", lf->filename));
  329 
  330         if (linker_file_lookup_set(lf, "modmetadata_set", &start,
  331             &stop, NULL) != 0) {
  332                 /*
  333                  * This fallback should be unnecessary, but if we get booted
  334                  * from boot2 instead of loader and we are missing our
  335                  * metadata then we have to try the best we can.
  336                  */
  337                 if (lf == linker_kernel_file) {
  338                         start = SET_BEGIN(modmetadata_set);
  339                         stop = SET_LIMIT(modmetadata_set);
  340                 } else
  341                         return (0);
  342         }
  343         first_error = 0;
  344         for (mdp = start; mdp < stop; mdp++) {
  345                 if ((*mdp)->md_type != MDT_MODULE)
  346                         continue;
  347                 moddata = (*mdp)->md_data;
  348                 KLD_DPF(FILE, ("Registering module %s in %s\n",
  349                     moddata->name, lf->filename));
  350                 error = module_register(moddata, lf);
  351                 if (error) {
  352                         printf("Module %s failed to register: %d\n",
  353                             moddata->name, error);
  354                         if (first_error == 0)
  355                                 first_error = error;
  356                 }
  357         }
  358         return (first_error);
  359 }
  360 
  361 static void
  362 linker_init_kernel_modules(void)
  363 {
  364 
  365         linker_file_register_modules(linker_kernel_file);
  366 }
  367 
  368 SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules,
  369     0);
  370 
  371 static int
  372 linker_load_file(const char *filename, linker_file_t *result)
  373 {
  374         linker_class_t lc;
  375         linker_file_t lf;
  376         int foundfile, error;
  377 
  378         /* Refuse to load modules if securelevel raised */
  379         if (prison0.pr_securelevel > 0)
  380                 return (EPERM);
  381 
  382         KLD_LOCK_ASSERT();
  383         lf = linker_find_file_by_name(filename);
  384         if (lf) {
  385                 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded,"
  386                     " incrementing refs\n", filename));
  387                 *result = lf;
  388                 lf->refs++;
  389                 return (0);
  390         }
  391         foundfile = 0;
  392         error = 0;
  393 
  394         /*
  395          * We do not need to protect (lock) classes here because there is
  396          * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY)
  397          * and there is no class deregistration mechanism at this time.
  398          */
  399         TAILQ_FOREACH(lc, &classes, link) {
  400                 KLD_DPF(FILE, ("linker_load_file: trying to load %s\n",
  401                     filename));
  402                 error = LINKER_LOAD_FILE(lc, filename, &lf);
  403                 /*
  404                  * If we got something other than ENOENT, then it exists but
  405                  * we cannot load it for some other reason.
  406                  */
  407                 if (error != ENOENT)
  408                         foundfile = 1;
  409                 if (lf) {
  410                         error = linker_file_register_modules(lf);
  411                         if (error == EEXIST) {
  412                                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
  413                                 return (error);
  414                         }
  415                         KLD_UNLOCK();
  416                         linker_file_register_sysctls(lf);
  417                         linker_file_sysinit(lf);
  418                         KLD_LOCK();
  419                         lf->flags |= LINKER_FILE_LINKED;
  420                         *result = lf;
  421                         return (0);
  422                 }
  423         }
  424         /*
  425          * Less than ideal, but tells the user whether it failed to load or
  426          * the module was not found.
  427          */
  428         if (foundfile) {
  429 
  430                 /*
  431                  * If the file type has not been recognized by the last try
  432                  * printout a message before to fail.
  433                  */
  434                 if (error == ENOSYS)
  435                         printf("linker_load_file: Unsupported file type\n");
  436 
  437                 /*
  438                  * Format not recognized or otherwise unloadable.
  439                  * When loading a module that is statically built into
  440                  * the kernel EEXIST percolates back up as the return
  441                  * value.  Preserve this so that apps like sysinstall
  442                  * can recognize this special case and not post bogus
  443                  * dialog boxes.
  444                  */
  445                 if (error != EEXIST)
  446                         error = ENOEXEC;
  447         } else
  448                 error = ENOENT;         /* Nothing found */
  449         return (error);
  450 }
  451 
  452 int
  453 linker_reference_module(const char *modname, struct mod_depend *verinfo,
  454     linker_file_t *result)
  455 {
  456         modlist_t mod;
  457         int error;
  458 
  459         KLD_LOCK();
  460         if ((mod = modlist_lookup2(modname, verinfo)) != NULL) {
  461                 *result = mod->container;
  462                 (*result)->refs++;
  463                 KLD_UNLOCK();
  464                 return (0);
  465         }
  466 
  467         error = linker_load_module(NULL, modname, NULL, verinfo, result);
  468         KLD_UNLOCK();
  469         return (error);
  470 }
  471 
  472 int
  473 linker_release_module(const char *modname, struct mod_depend *verinfo,
  474     linker_file_t lf)
  475 {
  476         modlist_t mod;
  477         int error;
  478 
  479         KLD_LOCK();
  480         if (lf == NULL) {
  481                 KASSERT(modname != NULL,
  482                     ("linker_release_module: no file or name"));
  483                 mod = modlist_lookup2(modname, verinfo);
  484                 if (mod == NULL) {
  485                         KLD_UNLOCK();
  486                         return (ESRCH);
  487                 }
  488                 lf = mod->container;
  489         } else
  490                 KASSERT(modname == NULL && verinfo == NULL,
  491                     ("linker_release_module: both file and name"));
  492         error = linker_file_unload(lf, LINKER_UNLOAD_NORMAL);
  493         KLD_UNLOCK();
  494         return (error);
  495 }
  496 
  497 static linker_file_t
  498 linker_find_file_by_name(const char *filename)
  499 {
  500         linker_file_t lf;
  501         char *koname;
  502 
  503         koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK);
  504         sprintf(koname, "%s.ko", filename);
  505 
  506         KLD_LOCK_ASSERT();
  507         TAILQ_FOREACH(lf, &linker_files, link) {
  508                 if (strcmp(lf->filename, koname) == 0)
  509                         break;
  510                 if (strcmp(lf->filename, filename) == 0)
  511                         break;
  512         }
  513         free(koname, M_LINKER);
  514         return (lf);
  515 }
  516 
  517 static linker_file_t
  518 linker_find_file_by_id(int fileid)
  519 {
  520         linker_file_t lf;
  521 
  522         KLD_LOCK_ASSERT();
  523         TAILQ_FOREACH(lf, &linker_files, link)
  524                 if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED)
  525                         break;
  526         return (lf);
  527 }
  528 
  529 int
  530 linker_file_foreach(linker_predicate_t *predicate, void *context)
  531 {
  532         linker_file_t lf;
  533         int retval = 0;
  534 
  535         KLD_LOCK();
  536         TAILQ_FOREACH(lf, &linker_files, link) {
  537                 retval = predicate(lf, context);
  538                 if (retval != 0)
  539                         break;
  540         }
  541         KLD_UNLOCK();
  542         return (retval);
  543 }
  544 
  545 linker_file_t
  546 linker_make_file(const char *pathname, linker_class_t lc)
  547 {
  548         linker_file_t lf;
  549         const char *filename;
  550 
  551         KLD_LOCK_ASSERT();
  552         filename = linker_basename(pathname);
  553 
  554         KLD_DPF(FILE, ("linker_make_file: new file, filename='%s' for pathname='%s'\n", filename, pathname));
  555         lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK);
  556         if (lf == NULL)
  557                 return (NULL);
  558         lf->refs = 1;
  559         lf->userrefs = 0;
  560         lf->flags = 0;
  561         lf->filename = linker_strdup(filename);
  562         lf->pathname = linker_strdup(pathname);
  563         LINKER_GET_NEXT_FILE_ID(lf->id);
  564         lf->ndeps = 0;
  565         lf->deps = NULL;
  566         lf->loadcnt = ++loadcnt;
  567         lf->sdt_probes = NULL;
  568         lf->sdt_nprobes = 0;
  569         STAILQ_INIT(&lf->common);
  570         TAILQ_INIT(&lf->modules);
  571         TAILQ_INSERT_TAIL(&linker_files, lf, link);
  572         return (lf);
  573 }
  574 
  575 int
  576 linker_file_unload(linker_file_t file, int flags)
  577 {
  578         module_t mod, next;
  579         modlist_t ml, nextml;
  580         struct common_symbol *cp;
  581         int error, i;
  582 
  583         /* Refuse to unload modules if securelevel raised. */
  584         if (prison0.pr_securelevel > 0)
  585                 return (EPERM);
  586 
  587         KLD_LOCK_ASSERT();
  588         KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs));
  589 
  590         /* Easy case of just dropping a reference. */
  591         if (file->refs > 1) {
  592                 file->refs--;
  593                 return (0);
  594         }
  595 
  596         KLD_DPF(FILE, ("linker_file_unload: file is unloading,"
  597             " informing modules\n"));
  598 
  599         /*
  600          * Quiesce all the modules to give them a chance to veto the unload.
  601          */
  602         MOD_SLOCK;
  603         for (mod = TAILQ_FIRST(&file->modules); mod;
  604              mod = module_getfnext(mod)) {
  605 
  606                 error = module_quiesce(mod);
  607                 if (error != 0 && flags != LINKER_UNLOAD_FORCE) {
  608                         KLD_DPF(FILE, ("linker_file_unload: module %s"
  609                             " vetoed unload\n", module_getname(mod)));
  610                         /*
  611                          * XXX: Do we need to tell all the quiesced modules
  612                          * that they can resume work now via a new module
  613                          * event?
  614                          */
  615                         MOD_SUNLOCK;
  616                         return (error);
  617                 }
  618         }
  619         MOD_SUNLOCK;
  620 
  621         /*
  622          * Inform any modules associated with this file that they are
  623          * being be unloaded.
  624          */
  625         MOD_XLOCK;
  626         for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) {
  627                 next = module_getfnext(mod);
  628                 MOD_XUNLOCK;
  629 
  630                 /*
  631                  * Give the module a chance to veto the unload.
  632                  */
  633                 if ((error = module_unload(mod)) != 0) {
  634                         KLD_DPF(FILE, ("linker_file_unload: module %s"
  635                             " failed unload\n", mod));
  636                         return (error);
  637                 }
  638                 MOD_XLOCK;
  639                 module_release(mod);
  640         }
  641         MOD_XUNLOCK;
  642 
  643         TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) {
  644                 if (ml->container == file) {
  645                         TAILQ_REMOVE(&found_modules, ml, link);
  646                         free(ml, M_LINKER);
  647                 }
  648         }
  649 
  650         /*
  651          * Don't try to run SYSUNINITs if we are unloaded due to a
  652          * link error.
  653          */
  654         if (file->flags & LINKER_FILE_LINKED) {
  655                 file->flags &= ~LINKER_FILE_LINKED;
  656                 KLD_UNLOCK();
  657                 linker_file_sysuninit(file);
  658                 linker_file_unregister_sysctls(file);
  659                 KLD_LOCK();
  660         }
  661         TAILQ_REMOVE(&linker_files, file, link);
  662 
  663         if (file->deps) {
  664                 for (i = 0; i < file->ndeps; i++)
  665                         linker_file_unload(file->deps[i], flags);
  666                 free(file->deps, M_LINKER);
  667                 file->deps = NULL;
  668         }
  669         while ((cp = STAILQ_FIRST(&file->common)) != NULL) {
  670                 STAILQ_REMOVE_HEAD(&file->common, link);
  671                 free(cp, M_LINKER);
  672         }
  673 
  674         LINKER_UNLOAD(file);
  675         if (file->filename) {
  676                 free(file->filename, M_LINKER);
  677                 file->filename = NULL;
  678         }
  679         if (file->pathname) {
  680                 free(file->pathname, M_LINKER);
  681                 file->pathname = NULL;
  682         }
  683         kobj_delete((kobj_t) file, M_LINKER);
  684         return (0);
  685 }
  686 
  687 int
  688 linker_ctf_get(linker_file_t file, linker_ctf_t *lc)
  689 {
  690         return (LINKER_CTF_GET(file, lc));
  691 }
  692 
  693 static int
  694 linker_file_add_dependency(linker_file_t file, linker_file_t dep)
  695 {
  696         linker_file_t *newdeps;
  697 
  698         KLD_LOCK_ASSERT();
  699         newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t *),
  700             M_LINKER, M_WAITOK | M_ZERO);
  701         if (newdeps == NULL)
  702                 return (ENOMEM);
  703 
  704         if (file->deps) {
  705                 bcopy(file->deps, newdeps,
  706                     file->ndeps * sizeof(linker_file_t *));
  707                 free(file->deps, M_LINKER);
  708         }
  709         file->deps = newdeps;
  710         file->deps[file->ndeps] = dep;
  711         file->ndeps++;
  712         return (0);
  713 }
  714 
  715 /*
  716  * Locate a linker set and its contents.  This is a helper function to avoid
  717  * linker_if.h exposure elsewhere.  Note: firstp and lastp are really void **.
  718  * This function is used in this file so we can avoid having lots of (void **)
  719  * casts.
  720  */
  721 int
  722 linker_file_lookup_set(linker_file_t file, const char *name,
  723     void *firstp, void *lastp, int *countp)
  724 {
  725         int error, locked;
  726 
  727         locked = KLD_LOCKED();
  728         if (!locked)
  729                 KLD_LOCK();
  730         error = LINKER_LOOKUP_SET(file, name, firstp, lastp, countp);
  731         if (!locked)
  732                 KLD_UNLOCK();
  733         return (error);
  734 }
  735 
  736 /*
  737  * List all functions in a file.
  738  */
  739 int
  740 linker_file_function_listall(linker_file_t lf,
  741     linker_function_nameval_callback_t callback_func, void *arg)
  742 {
  743         return (LINKER_EACH_FUNCTION_NAMEVAL(lf, callback_func, arg));
  744 }
  745 
  746 caddr_t
  747 linker_file_lookup_symbol(linker_file_t file, const char *name, int deps)
  748 {
  749         caddr_t sym;
  750         int locked;
  751 
  752         locked = KLD_LOCKED();
  753         if (!locked)
  754                 KLD_LOCK();
  755         sym = linker_file_lookup_symbol_internal(file, name, deps);
  756         if (!locked)
  757                 KLD_UNLOCK();
  758         return (sym);
  759 }
  760 
  761 static caddr_t
  762 linker_file_lookup_symbol_internal(linker_file_t file, const char *name,
  763     int deps)
  764 {
  765         c_linker_sym_t sym;
  766         linker_symval_t symval;
  767         caddr_t address;
  768         size_t common_size = 0;
  769         int i;
  770 
  771         KLD_LOCK_ASSERT();
  772         KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n",
  773             file, name, deps));
  774 
  775         if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) {
  776                 LINKER_SYMBOL_VALUES(file, sym, &symval);
  777                 if (symval.value == 0)
  778                         /*
  779                          * For commons, first look them up in the
  780                          * dependencies and only allocate space if not found
  781                          * there.
  782                          */
  783                         common_size = symval.size;
  784                 else {
  785                         KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol"
  786                             ".value=%p\n", symval.value));
  787                         return (symval.value);
  788                 }
  789         }
  790         if (deps) {
  791                 for (i = 0; i < file->ndeps; i++) {
  792                         address = linker_file_lookup_symbol_internal(
  793                             file->deps[i], name, 0);
  794                         if (address) {
  795                                 KLD_DPF(SYM, ("linker_file_lookup_symbol:"
  796                                     " deps value=%p\n", address));
  797                                 return (address);
  798                         }
  799                 }
  800         }
  801         if (common_size > 0) {
  802                 /*
  803                  * This is a common symbol which was not found in the
  804                  * dependencies.  We maintain a simple common symbol table in
  805                  * the file object.
  806                  */
  807                 struct common_symbol *cp;
  808 
  809                 STAILQ_FOREACH(cp, &file->common, link) {
  810                         if (strcmp(cp->name, name) == 0) {
  811                                 KLD_DPF(SYM, ("linker_file_lookup_symbol:"
  812                                     " old common value=%p\n", cp->address));
  813                                 return (cp->address);
  814                         }
  815                 }
  816                 /*
  817                  * Round the symbol size up to align.
  818                  */
  819                 common_size = (common_size + sizeof(int) - 1) & -sizeof(int);
  820                 cp = malloc(sizeof(struct common_symbol)
  821                     + common_size + strlen(name) + 1, M_LINKER,
  822                     M_WAITOK | M_ZERO);
  823                 cp->address = (caddr_t)(cp + 1);
  824                 cp->name = cp->address + common_size;
  825                 strcpy(cp->name, name);
  826                 bzero(cp->address, common_size);
  827                 STAILQ_INSERT_TAIL(&file->common, cp, link);
  828 
  829                 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common"
  830                     " value=%p\n", cp->address));
  831                 return (cp->address);
  832         }
  833         KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n"));
  834         return (0);
  835 }
  836 
  837 /*
  838  * Both DDB and stack(9) rely on the kernel linker to provide forward and
  839  * backward lookup of symbols.  However, DDB and sometimes stack(9) need to
  840  * do this in a lockfree manner.  We provide a set of internal helper
  841  * routines to perform these operations without locks, and then wrappers that
  842  * optionally lock.
  843  *
  844  * linker_debug_lookup() is ifdef DDB as currently it's only used by DDB.
  845  */
  846 #ifdef DDB
  847 static int
  848 linker_debug_lookup(const char *symstr, c_linker_sym_t *sym)
  849 {
  850         linker_file_t lf;
  851 
  852         TAILQ_FOREACH(lf, &linker_files, link) {
  853                 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0)
  854                         return (0);
  855         }
  856         return (ENOENT);
  857 }
  858 #endif
  859 
  860 static int
  861 linker_debug_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
  862 {
  863         linker_file_t lf;
  864         c_linker_sym_t best, es;
  865         u_long diff, bestdiff, off;
  866 
  867         best = 0;
  868         off = (uintptr_t)value;
  869         bestdiff = off;
  870         TAILQ_FOREACH(lf, &linker_files, link) {
  871                 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0)
  872                         continue;
  873                 if (es != 0 && diff < bestdiff) {
  874                         best = es;
  875                         bestdiff = diff;
  876                 }
  877                 if (bestdiff == 0)
  878                         break;
  879         }
  880         if (best) {
  881                 *sym = best;
  882                 *diffp = bestdiff;
  883                 return (0);
  884         } else {
  885                 *sym = 0;
  886                 *diffp = off;
  887                 return (ENOENT);
  888         }
  889 }
  890 
  891 static int
  892 linker_debug_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
  893 {
  894         linker_file_t lf;
  895 
  896         TAILQ_FOREACH(lf, &linker_files, link) {
  897                 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0)
  898                         return (0);
  899         }
  900         return (ENOENT);
  901 }
  902 
  903 static int
  904 linker_debug_search_symbol_name(caddr_t value, char *buf, u_int buflen,
  905     long *offset)
  906 {
  907         linker_symval_t symval;
  908         c_linker_sym_t sym;
  909         int error;
  910 
  911         *offset = 0;
  912         error = linker_debug_search_symbol(value, &sym, offset);
  913         if (error)
  914                 return (error);
  915         error = linker_debug_symbol_values(sym, &symval);
  916         if (error)
  917                 return (error);
  918         strlcpy(buf, symval.name, buflen);
  919         return (0);
  920 }
  921 
  922 #ifdef DDB
  923 /*
  924  * DDB Helpers.  DDB has to look across multiple files with their own symbol
  925  * tables and string tables.
  926  *
  927  * Note that we do not obey list locking protocols here.  We really don't need
  928  * DDB to hang because somebody's got the lock held.  We'll take the chance
  929  * that the files list is inconsistant instead.
  930  */
  931 int
  932 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym)
  933 {
  934 
  935         return (linker_debug_lookup(symstr, sym));
  936 }
  937 
  938 int
  939 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
  940 {
  941 
  942         return (linker_debug_search_symbol(value, sym, diffp));
  943 }
  944 
  945 int
  946 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
  947 {
  948 
  949         return (linker_debug_symbol_values(sym, symval));
  950 }
  951 
  952 int
  953 linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen,
  954     long *offset)
  955 {
  956 
  957         return (linker_debug_search_symbol_name(value, buf, buflen, offset));
  958 }
  959 #endif
  960 
  961 /*
  962  * stack(9) helper for non-debugging environemnts.  Unlike DDB helpers, we do
  963  * obey locking protocols, and offer a significantly less complex interface.
  964  */
  965 int
  966 linker_search_symbol_name(caddr_t value, char *buf, u_int buflen,
  967     long *offset)
  968 {
  969         int error;
  970 
  971         KLD_LOCK();
  972         error = linker_debug_search_symbol_name(value, buf, buflen, offset);
  973         KLD_UNLOCK();
  974         return (error);
  975 }
  976 
  977 /*
  978  * Syscalls.
  979  */
  980 int
  981 kern_kldload(struct thread *td, const char *file, int *fileid)
  982 {
  983 #ifdef HWPMC_HOOKS
  984         struct pmckern_map_in pkm;
  985 #endif
  986         const char *kldname, *modname;
  987         linker_file_t lf;
  988         int error;
  989 
  990         if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
  991                 return (error);
  992 
  993         if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0)
  994                 return (error);
  995 
  996         /*
  997          * It is possible that kldloaded module will attach a new ifnet,
  998          * so vnet context must be set when this ocurs.
  999          */
 1000         CURVNET_SET(TD_TO_VNET(td));
 1001 
 1002         /*
 1003          * If file does not contain a qualified name or any dot in it
 1004          * (kldname.ko, or kldname.ver.ko) treat it as an interface
 1005          * name.
 1006          */
 1007         if (index(file, '/') || index(file, '.')) {
 1008                 kldname = file;
 1009                 modname = NULL;
 1010         } else {
 1011                 kldname = NULL;
 1012                 modname = file;
 1013         }
 1014 
 1015         KLD_LOCK();
 1016         error = linker_load_module(kldname, modname, NULL, NULL, &lf);
 1017         if (error)
 1018                 goto unlock;
 1019 #ifdef HWPMC_HOOKS
 1020         pkm.pm_file = lf->filename;
 1021         pkm.pm_address = (uintptr_t) lf->address;
 1022         PMC_CALL_HOOK(td, PMC_FN_KLD_LOAD, (void *) &pkm);
 1023 #endif
 1024         lf->userrefs++;
 1025         if (fileid != NULL)
 1026                 *fileid = lf->id;
 1027 unlock:
 1028         KLD_UNLOCK();
 1029         CURVNET_RESTORE();
 1030         return (error);
 1031 }
 1032 
 1033 int
 1034 kldload(struct thread *td, struct kldload_args *uap)
 1035 {
 1036         char *pathname = NULL;
 1037         int error, fileid;
 1038 
 1039         td->td_retval[0] = -1;
 1040 
 1041         pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
 1042         error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL);
 1043         if (error == 0) {
 1044                 error = kern_kldload(td, pathname, &fileid);
 1045                 if (error == 0)
 1046                         td->td_retval[0] = fileid;
 1047         }
 1048         free(pathname, M_TEMP);
 1049         return (error);
 1050 }
 1051 
 1052 int
 1053 kern_kldunload(struct thread *td, int fileid, int flags)
 1054 {
 1055 #ifdef HWPMC_HOOKS
 1056         struct pmckern_map_out pkm;
 1057 #endif
 1058         linker_file_t lf;
 1059         int error = 0;
 1060 
 1061         if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
 1062                 return (error);
 1063 
 1064         if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0)
 1065                 return (error);
 1066 
 1067         CURVNET_SET(TD_TO_VNET(td));
 1068         KLD_LOCK();
 1069         lf = linker_find_file_by_id(fileid);
 1070         if (lf) {
 1071                 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs));
 1072 
 1073                 /* Check if there are DTrace probes enabled on this file. */
 1074                 if (lf->nenabled > 0) {
 1075                         printf("kldunload: attempt to unload file that has"
 1076                             " DTrace probes enabled\n");
 1077                         error = EBUSY;
 1078                 } else if (lf->userrefs == 0) {
 1079                         /*
 1080                          * XXX: maybe LINKER_UNLOAD_FORCE should override ?
 1081                          */
 1082                         printf("kldunload: attempt to unload file that was"
 1083                             " loaded by the kernel\n");
 1084                         error = EBUSY;
 1085                 } else {
 1086 #ifdef HWPMC_HOOKS
 1087                         /* Save data needed by hwpmc(4) before unloading. */
 1088                         pkm.pm_address = (uintptr_t) lf->address;
 1089                         pkm.pm_size = lf->size;
 1090 #endif
 1091                         lf->userrefs--;
 1092                         error = linker_file_unload(lf, flags);
 1093                         if (error)
 1094                                 lf->userrefs++;
 1095                 }
 1096         } else
 1097                 error = ENOENT;
 1098 
 1099 #ifdef HWPMC_HOOKS
 1100         if (error == 0)
 1101                 PMC_CALL_HOOK(td, PMC_FN_KLD_UNLOAD, (void *) &pkm);
 1102 #endif
 1103         KLD_UNLOCK();
 1104         CURVNET_RESTORE();
 1105         return (error);
 1106 }
 1107 
 1108 int
 1109 kldunload(struct thread *td, struct kldunload_args *uap)
 1110 {
 1111 
 1112         return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL));
 1113 }
 1114 
 1115 int
 1116 kldunloadf(struct thread *td, struct kldunloadf_args *uap)
 1117 {
 1118 
 1119         if (uap->flags != LINKER_UNLOAD_NORMAL &&
 1120             uap->flags != LINKER_UNLOAD_FORCE)
 1121                 return (EINVAL);
 1122         return (kern_kldunload(td, uap->fileid, uap->flags));
 1123 }
 1124 
 1125 int
 1126 kldfind(struct thread *td, struct kldfind_args *uap)
 1127 {
 1128         char *pathname;
 1129         const char *filename;
 1130         linker_file_t lf;
 1131         int error;
 1132 
 1133 #ifdef MAC
 1134         error = mac_kld_check_stat(td->td_ucred);
 1135         if (error)
 1136                 return (error);
 1137 #endif
 1138 
 1139         td->td_retval[0] = -1;
 1140 
 1141         pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
 1142         if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0)
 1143                 goto out;
 1144 
 1145         filename = linker_basename(pathname);
 1146         KLD_LOCK();
 1147         lf = linker_find_file_by_name(filename);
 1148         if (lf)
 1149                 td->td_retval[0] = lf->id;
 1150         else
 1151                 error = ENOENT;
 1152         KLD_UNLOCK();
 1153 out:
 1154         free(pathname, M_TEMP);
 1155         return (error);
 1156 }
 1157 
 1158 int
 1159 kldnext(struct thread *td, struct kldnext_args *uap)
 1160 {
 1161         linker_file_t lf;
 1162         int error = 0;
 1163 
 1164 #ifdef MAC
 1165         error = mac_kld_check_stat(td->td_ucred);
 1166         if (error)
 1167                 return (error);
 1168 #endif
 1169 
 1170         KLD_LOCK();
 1171         if (uap->fileid == 0)
 1172                 lf = TAILQ_FIRST(&linker_files);
 1173         else {
 1174                 lf = linker_find_file_by_id(uap->fileid);
 1175                 if (lf == NULL) {
 1176                         error = ENOENT;
 1177                         goto out;
 1178                 }
 1179                 lf = TAILQ_NEXT(lf, link);
 1180         }
 1181 
 1182         /* Skip partially loaded files. */
 1183         while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED))
 1184                 lf = TAILQ_NEXT(lf, link);
 1185 
 1186         if (lf)
 1187                 td->td_retval[0] = lf->id;
 1188         else
 1189                 td->td_retval[0] = 0;
 1190 out:
 1191         KLD_UNLOCK();
 1192         return (error);
 1193 }
 1194 
 1195 int
 1196 kldstat(struct thread *td, struct kldstat_args *uap)
 1197 {
 1198         struct kld_file_stat stat;
 1199         linker_file_t lf;
 1200         int error, namelen, version, version_num;
 1201 
 1202         /*
 1203          * Check the version of the user's structure.
 1204          */
 1205         if ((error = copyin(&uap->stat->version, &version, sizeof(version))) != 0)
 1206                 return (error);
 1207         if (version == sizeof(struct kld_file_stat_1))
 1208                 version_num = 1;
 1209         else if (version == sizeof(struct kld_file_stat))
 1210                 version_num = 2;
 1211         else
 1212                 return (EINVAL);
 1213 
 1214 #ifdef MAC
 1215         error = mac_kld_check_stat(td->td_ucred);
 1216         if (error)
 1217                 return (error);
 1218 #endif
 1219 
 1220         KLD_LOCK();
 1221         lf = linker_find_file_by_id(uap->fileid);
 1222         if (lf == NULL) {
 1223                 KLD_UNLOCK();
 1224                 return (ENOENT);
 1225         }
 1226 
 1227         /* Version 1 fields: */
 1228         namelen = strlen(lf->filename) + 1;
 1229         if (namelen > MAXPATHLEN)
 1230                 namelen = MAXPATHLEN;
 1231         bcopy(lf->filename, &stat.name[0], namelen);
 1232         stat.refs = lf->refs;
 1233         stat.id = lf->id;
 1234         stat.address = lf->address;
 1235         stat.size = lf->size;
 1236         if (version_num > 1) {
 1237                 /* Version 2 fields: */
 1238                 namelen = strlen(lf->pathname) + 1;
 1239                 if (namelen > MAXPATHLEN)
 1240                         namelen = MAXPATHLEN;
 1241                 bcopy(lf->pathname, &stat.pathname[0], namelen);
 1242         }
 1243         KLD_UNLOCK();
 1244 
 1245         td->td_retval[0] = 0;
 1246 
 1247         return (copyout(&stat, uap->stat, version));
 1248 }
 1249 
 1250 int
 1251 kldfirstmod(struct thread *td, struct kldfirstmod_args *uap)
 1252 {
 1253         linker_file_t lf;
 1254         module_t mp;
 1255         int error = 0;
 1256 
 1257 #ifdef MAC
 1258         error = mac_kld_check_stat(td->td_ucred);
 1259         if (error)
 1260                 return (error);
 1261 #endif
 1262 
 1263         KLD_LOCK();
 1264         lf = linker_find_file_by_id(uap->fileid);
 1265         if (lf) {
 1266                 MOD_SLOCK;
 1267                 mp = TAILQ_FIRST(&lf->modules);
 1268                 if (mp != NULL)
 1269                         td->td_retval[0] = module_getid(mp);
 1270                 else
 1271                         td->td_retval[0] = 0;
 1272                 MOD_SUNLOCK;
 1273         } else
 1274                 error = ENOENT;
 1275         KLD_UNLOCK();
 1276         return (error);
 1277 }
 1278 
 1279 int
 1280 kldsym(struct thread *td, struct kldsym_args *uap)
 1281 {
 1282         char *symstr = NULL;
 1283         c_linker_sym_t sym;
 1284         linker_symval_t symval;
 1285         linker_file_t lf;
 1286         struct kld_sym_lookup lookup;
 1287         int error = 0;
 1288 
 1289 #ifdef MAC
 1290         error = mac_kld_check_stat(td->td_ucred);
 1291         if (error)
 1292                 return (error);
 1293 #endif
 1294 
 1295         if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0)
 1296                 return (error);
 1297         if (lookup.version != sizeof(lookup) ||
 1298             uap->cmd != KLDSYM_LOOKUP)
 1299                 return (EINVAL);
 1300         symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
 1301         if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0)
 1302                 goto out;
 1303         KLD_LOCK();
 1304         if (uap->fileid != 0) {
 1305                 lf = linker_find_file_by_id(uap->fileid);
 1306                 if (lf == NULL)
 1307                         error = ENOENT;
 1308                 else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
 1309                     LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
 1310                         lookup.symvalue = (uintptr_t) symval.value;
 1311                         lookup.symsize = symval.size;
 1312                         error = copyout(&lookup, uap->data, sizeof(lookup));
 1313                 } else
 1314                         error = ENOENT;
 1315         } else {
 1316                 TAILQ_FOREACH(lf, &linker_files, link) {
 1317                         if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
 1318                             LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
 1319                                 lookup.symvalue = (uintptr_t)symval.value;
 1320                                 lookup.symsize = symval.size;
 1321                                 error = copyout(&lookup, uap->data,
 1322                                     sizeof(lookup));
 1323                                 break;
 1324                         }
 1325                 }
 1326                 if (lf == NULL)
 1327                         error = ENOENT;
 1328         }
 1329         KLD_UNLOCK();
 1330 out:
 1331         free(symstr, M_TEMP);
 1332         return (error);
 1333 }
 1334 
 1335 /*
 1336  * Preloaded module support
 1337  */
 1338 
 1339 static modlist_t
 1340 modlist_lookup(const char *name, int ver)
 1341 {
 1342         modlist_t mod;
 1343 
 1344         TAILQ_FOREACH(mod, &found_modules, link) {
 1345                 if (strcmp(mod->name, name) == 0 &&
 1346                     (ver == 0 || mod->version == ver))
 1347                         return (mod);
 1348         }
 1349         return (NULL);
 1350 }
 1351 
 1352 static modlist_t
 1353 modlist_lookup2(const char *name, struct mod_depend *verinfo)
 1354 {
 1355         modlist_t mod, bestmod;
 1356         int ver;
 1357 
 1358         if (verinfo == NULL)
 1359                 return (modlist_lookup(name, 0));
 1360         bestmod = NULL;
 1361         TAILQ_FOREACH(mod, &found_modules, link) {
 1362                 if (strcmp(mod->name, name) != 0)
 1363                         continue;
 1364                 ver = mod->version;
 1365                 if (ver == verinfo->md_ver_preferred)
 1366                         return (mod);
 1367                 if (ver >= verinfo->md_ver_minimum &&
 1368                     ver <= verinfo->md_ver_maximum &&
 1369                     (bestmod == NULL || ver > bestmod->version))
 1370                         bestmod = mod;
 1371         }
 1372         return (bestmod);
 1373 }
 1374 
 1375 static modlist_t
 1376 modlist_newmodule(const char *modname, int version, linker_file_t container)
 1377 {
 1378         modlist_t mod;
 1379 
 1380         mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO);
 1381         if (mod == NULL)
 1382                 panic("no memory for module list");
 1383         mod->container = container;
 1384         mod->name = modname;
 1385         mod->version = version;
 1386         TAILQ_INSERT_TAIL(&found_modules, mod, link);
 1387         return (mod);
 1388 }
 1389 
 1390 static void
 1391 linker_addmodules(linker_file_t lf, struct mod_metadata **start,
 1392     struct mod_metadata **stop, int preload)
 1393 {
 1394         struct mod_metadata *mp, **mdp;
 1395         const char *modname;
 1396         int ver;
 1397 
 1398         for (mdp = start; mdp < stop; mdp++) {
 1399                 mp = *mdp;
 1400                 if (mp->md_type != MDT_VERSION)
 1401                         continue;
 1402                 modname = mp->md_cval;
 1403                 ver = ((struct mod_version *)mp->md_data)->mv_version;
 1404                 if (modlist_lookup(modname, ver) != NULL) {
 1405                         printf("module %s already present!\n", modname);
 1406                         /* XXX what can we do? this is a build error. :-( */
 1407                         continue;
 1408                 }
 1409                 modlist_newmodule(modname, ver, lf);
 1410         }
 1411 }
 1412 
 1413 static void
 1414 linker_preload(void *arg)
 1415 {
 1416         caddr_t modptr;
 1417         const char *modname, *nmodname;
 1418         char *modtype;
 1419         linker_file_t lf, nlf;
 1420         linker_class_t lc;
 1421         int error;
 1422         linker_file_list_t loaded_files;
 1423         linker_file_list_t depended_files;
 1424         struct mod_metadata *mp, *nmp;
 1425         struct mod_metadata **start, **stop, **mdp, **nmdp;
 1426         struct mod_depend *verinfo;
 1427         int nver;
 1428         int resolves;
 1429         modlist_t mod;
 1430         struct sysinit **si_start, **si_stop;
 1431 
 1432         TAILQ_INIT(&loaded_files);
 1433         TAILQ_INIT(&depended_files);
 1434         TAILQ_INIT(&found_modules);
 1435         error = 0;
 1436 
 1437         modptr = NULL;
 1438         while ((modptr = preload_search_next_name(modptr)) != NULL) {
 1439                 modname = (char *)preload_search_info(modptr, MODINFO_NAME);
 1440                 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE);
 1441                 if (modname == NULL) {
 1442                         printf("Preloaded module at %p does not have a"
 1443                             " name!\n", modptr);
 1444                         continue;
 1445                 }
 1446                 if (modtype == NULL) {
 1447                         printf("Preloaded module at %p does not have a type!\n",
 1448                             modptr);
 1449                         continue;
 1450                 }
 1451                 if (bootverbose)
 1452                         printf("Preloaded %s \"%s\" at %p.\n", modtype, modname,
 1453                             modptr);
 1454                 lf = NULL;
 1455                 TAILQ_FOREACH(lc, &classes, link) {
 1456                         error = LINKER_LINK_PRELOAD(lc, modname, &lf);
 1457                         if (!error)
 1458                                 break;
 1459                         lf = NULL;
 1460                 }
 1461                 if (lf)
 1462                         TAILQ_INSERT_TAIL(&loaded_files, lf, loaded);
 1463         }
 1464 
 1465         /*
 1466          * First get a list of stuff in the kernel.
 1467          */
 1468         if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start,
 1469             &stop, NULL) == 0)
 1470                 linker_addmodules(linker_kernel_file, start, stop, 1);
 1471 
 1472         /*
 1473          * This is a once-off kinky bubble sort to resolve relocation
 1474          * dependency requirements.
 1475          */
 1476 restart:
 1477         TAILQ_FOREACH(lf, &loaded_files, loaded) {
 1478                 error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
 1479                     &stop, NULL);
 1480                 /*
 1481                  * First, look to see if we would successfully link with this
 1482                  * stuff.
 1483                  */
 1484                 resolves = 1;   /* unless we know otherwise */
 1485                 if (!error) {
 1486                         for (mdp = start; mdp < stop; mdp++) {
 1487                                 mp = *mdp;
 1488                                 if (mp->md_type != MDT_DEPEND)
 1489                                         continue;
 1490                                 modname = mp->md_cval;
 1491                                 verinfo = mp->md_data;
 1492                                 for (nmdp = start; nmdp < stop; nmdp++) {
 1493                                         nmp = *nmdp;
 1494                                         if (nmp->md_type != MDT_VERSION)
 1495                                                 continue;
 1496                                         nmodname = nmp->md_cval;
 1497                                         if (strcmp(modname, nmodname) == 0)
 1498                                                 break;
 1499                                 }
 1500                                 if (nmdp < stop)   /* it's a self reference */
 1501                                         continue;
 1502 
 1503                                 /*
 1504                                  * ok, the module isn't here yet, we
 1505                                  * are not finished
 1506                                  */
 1507                                 if (modlist_lookup2(modname, verinfo) == NULL)
 1508                                         resolves = 0;
 1509                         }
 1510                 }
 1511                 /*
 1512                  * OK, if we found our modules, we can link.  So, "provide"
 1513                  * the modules inside and add it to the end of the link order
 1514                  * list.
 1515                  */
 1516                 if (resolves) {
 1517                         if (!error) {
 1518                                 for (mdp = start; mdp < stop; mdp++) {
 1519                                         mp = *mdp;
 1520                                         if (mp->md_type != MDT_VERSION)
 1521                                                 continue;
 1522                                         modname = mp->md_cval;
 1523                                         nver = ((struct mod_version *)
 1524                                             mp->md_data)->mv_version;
 1525                                         if (modlist_lookup(modname,
 1526                                             nver) != NULL) {
 1527                                                 printf("module %s already"
 1528                                                     " present!\n", modname);
 1529                                                 TAILQ_REMOVE(&loaded_files,
 1530                                                     lf, loaded);
 1531                                                 linker_file_unload(lf,
 1532                                                     LINKER_UNLOAD_FORCE);
 1533                                                 /* we changed tailq next ptr */
 1534                                                 goto restart;
 1535                                         }
 1536                                         modlist_newmodule(modname, nver, lf);
 1537                                 }
 1538                         }
 1539                         TAILQ_REMOVE(&loaded_files, lf, loaded);
 1540                         TAILQ_INSERT_TAIL(&depended_files, lf, loaded);
 1541                         /*
 1542                          * Since we provided modules, we need to restart the
 1543                          * sort so that the previous files that depend on us
 1544                          * have a chance. Also, we've busted the tailq next
 1545                          * pointer with the REMOVE.
 1546                          */
 1547                         goto restart;
 1548                 }
 1549         }
 1550 
 1551         /*
 1552          * At this point, we check to see what could not be resolved..
 1553          */
 1554         while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) {
 1555                 TAILQ_REMOVE(&loaded_files, lf, loaded);
 1556                 printf("KLD file %s is missing dependencies\n", lf->filename);
 1557                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 1558         }
 1559 
 1560         /*
 1561          * We made it. Finish off the linking in the order we determined.
 1562          */
 1563         TAILQ_FOREACH_SAFE(lf, &depended_files, loaded, nlf) {
 1564                 if (linker_kernel_file) {
 1565                         linker_kernel_file->refs++;
 1566                         error = linker_file_add_dependency(lf,
 1567                             linker_kernel_file);
 1568                         if (error)
 1569                                 panic("cannot add dependency");
 1570                 }
 1571                 lf->userrefs++; /* so we can (try to) kldunload it */
 1572                 error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
 1573                     &stop, NULL);
 1574                 if (!error) {
 1575                         for (mdp = start; mdp < stop; mdp++) {
 1576                                 mp = *mdp;
 1577                                 if (mp->md_type != MDT_DEPEND)
 1578                                         continue;
 1579                                 modname = mp->md_cval;
 1580                                 verinfo = mp->md_data;
 1581                                 mod = modlist_lookup2(modname, verinfo);
 1582                                 /* Don't count self-dependencies */
 1583                                 if (lf == mod->container)
 1584                                         continue;
 1585                                 mod->container->refs++;
 1586                                 error = linker_file_add_dependency(lf,
 1587                                     mod->container);
 1588                                 if (error)
 1589                                         panic("cannot add dependency");
 1590                         }
 1591                 }
 1592                 /*
 1593                  * Now do relocation etc using the symbol search paths
 1594                  * established by the dependencies
 1595                  */
 1596                 error = LINKER_LINK_PRELOAD_FINISH(lf);
 1597                 if (error) {
 1598                         TAILQ_REMOVE(&depended_files, lf, loaded);
 1599                         printf("KLD file %s - could not finalize loading\n",
 1600                             lf->filename);
 1601                         linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 1602                         continue;
 1603                 }
 1604                 linker_file_register_modules(lf);
 1605                 if (linker_file_lookup_set(lf, "sysinit_set", &si_start,
 1606                     &si_stop, NULL) == 0)
 1607                         sysinit_add(si_start, si_stop);
 1608                 linker_file_register_sysctls(lf);
 1609                 lf->flags |= LINKER_FILE_LINKED;
 1610         }
 1611         /* woohoo! we made it! */
 1612 }
 1613 
 1614 SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0);
 1615 
 1616 /*
 1617  * Search for a not-loaded module by name.
 1618  *
 1619  * Modules may be found in the following locations:
 1620  *
 1621  * - preloaded (result is just the module name) - on disk (result is full path
 1622  * to module)
 1623  *
 1624  * If the module name is qualified in any way (contains path, etc.) the we
 1625  * simply return a copy of it.
 1626  *
 1627  * The search path can be manipulated via sysctl.  Note that we use the ';'
 1628  * character as a separator to be consistent with the bootloader.
 1629  */
 1630 
 1631 static char linker_hintfile[] = "linker.hints";
 1632 static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules";
 1633 
 1634 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path,
 1635     sizeof(linker_path), "module load search path");
 1636 
 1637 TUNABLE_STR("module_path", linker_path, sizeof(linker_path));
 1638 
 1639 static char *linker_ext_list[] = {
 1640         "",
 1641         ".ko",
 1642         NULL
 1643 };
 1644 
 1645 /*
 1646  * Check if file actually exists either with or without extension listed in
 1647  * the linker_ext_list. (probably should be generic for the rest of the
 1648  * kernel)
 1649  */
 1650 static char *
 1651 linker_lookup_file(const char *path, int pathlen, const char *name,
 1652     int namelen, struct vattr *vap)
 1653 {
 1654         struct nameidata nd;
 1655         struct thread *td = curthread;  /* XXX */
 1656         char *result, **cpp, *sep;
 1657         int error, len, extlen, reclen, flags, vfslocked;
 1658         enum vtype type;
 1659 
 1660         extlen = 0;
 1661         for (cpp = linker_ext_list; *cpp; cpp++) {
 1662                 len = strlen(*cpp);
 1663                 if (len > extlen)
 1664                         extlen = len;
 1665         }
 1666         extlen++;               /* trailing '\0' */
 1667         sep = (path[pathlen - 1] != '/') ? "/" : "";
 1668 
 1669         reclen = pathlen + strlen(sep) + namelen + extlen + 1;
 1670         result = malloc(reclen, M_LINKER, M_WAITOK);
 1671         for (cpp = linker_ext_list; *cpp; cpp++) {
 1672                 snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep,
 1673                     namelen, name, *cpp);
 1674                 /*
 1675                  * Attempt to open the file, and return the path if
 1676                  * we succeed and it's a regular file.
 1677                  */
 1678                 NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, result, td);
 1679                 flags = FREAD;
 1680                 error = vn_open(&nd, &flags, 0, NULL);
 1681                 if (error == 0) {
 1682                         vfslocked = NDHASGIANT(&nd);
 1683                         NDFREE(&nd, NDF_ONLY_PNBUF);
 1684                         type = nd.ni_vp->v_type;
 1685                         if (vap)
 1686                                 VOP_GETATTR(nd.ni_vp, vap, td->td_ucred);
 1687                         VOP_UNLOCK(nd.ni_vp, 0);
 1688                         vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
 1689                         VFS_UNLOCK_GIANT(vfslocked);
 1690                         if (type == VREG)
 1691                                 return (result);
 1692                 }
 1693         }
 1694         free(result, M_LINKER);
 1695         return (NULL);
 1696 }
 1697 
 1698 #define INT_ALIGN(base, ptr)    ptr =                                   \
 1699         (base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1))
 1700 
 1701 /*
 1702  * Lookup KLD which contains requested module in the "linker.hints" file. If
 1703  * version specification is available, then try to find the best KLD.
 1704  * Otherwise just find the latest one.
 1705  */
 1706 static char *
 1707 linker_hints_lookup(const char *path, int pathlen, const char *modname,
 1708     int modnamelen, struct mod_depend *verinfo)
 1709 {
 1710         struct thread *td = curthread;  /* XXX */
 1711         struct ucred *cred = td ? td->td_ucred : NULL;
 1712         struct nameidata nd;
 1713         struct vattr vattr, mattr;
 1714         u_char *hints = NULL;
 1715         u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep;
 1716         int error, ival, bestver, *intp, reclen, found, flags, clen, blen;
 1717         int vfslocked = 0;
 1718 
 1719         result = NULL;
 1720         bestver = found = 0;
 1721 
 1722         sep = (path[pathlen - 1] != '/') ? "/" : "";
 1723         reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen +
 1724             strlen(sep) + 1;
 1725         pathbuf = malloc(reclen, M_LINKER, M_WAITOK);
 1726         snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep,
 1727             linker_hintfile);
 1728 
 1729         NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, pathbuf, td);
 1730         flags = FREAD;
 1731         error = vn_open(&nd, &flags, 0, NULL);
 1732         if (error)
 1733                 goto bad;
 1734         vfslocked = NDHASGIANT(&nd);
 1735         NDFREE(&nd, NDF_ONLY_PNBUF);
 1736         if (nd.ni_vp->v_type != VREG)
 1737                 goto bad;
 1738         best = cp = NULL;
 1739         error = VOP_GETATTR(nd.ni_vp, &vattr, cred);
 1740         if (error)
 1741                 goto bad;
 1742         /*
 1743          * XXX: we need to limit this number to some reasonable value
 1744          */
 1745         if (vattr.va_size > 100 * 1024) {
 1746                 printf("hints file too large %ld\n", (long)vattr.va_size);
 1747                 goto bad;
 1748         }
 1749         hints = malloc(vattr.va_size, M_TEMP, M_WAITOK);
 1750         if (hints == NULL)
 1751                 goto bad;
 1752         error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0,
 1753             UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td);
 1754         if (error)
 1755                 goto bad;
 1756         VOP_UNLOCK(nd.ni_vp, 0);
 1757         vn_close(nd.ni_vp, FREAD, cred, td);
 1758         VFS_UNLOCK_GIANT(vfslocked);
 1759         nd.ni_vp = NULL;
 1760         if (reclen != 0) {
 1761                 printf("can't read %d\n", reclen);
 1762                 goto bad;
 1763         }
 1764         intp = (int *)hints;
 1765         ival = *intp++;
 1766         if (ival != LINKER_HINTS_VERSION) {
 1767                 printf("hints file version mismatch %d\n", ival);
 1768                 goto bad;
 1769         }
 1770         bufend = hints + vattr.va_size;
 1771         recptr = (u_char *)intp;
 1772         clen = blen = 0;
 1773         while (recptr < bufend && !found) {
 1774                 intp = (int *)recptr;
 1775                 reclen = *intp++;
 1776                 ival = *intp++;
 1777                 cp = (char *)intp;
 1778                 switch (ival) {
 1779                 case MDT_VERSION:
 1780                         clen = *cp++;
 1781                         if (clen != modnamelen || bcmp(cp, modname, clen) != 0)
 1782                                 break;
 1783                         cp += clen;
 1784                         INT_ALIGN(hints, cp);
 1785                         ival = *(int *)cp;
 1786                         cp += sizeof(int);
 1787                         clen = *cp++;
 1788                         if (verinfo == NULL ||
 1789                             ival == verinfo->md_ver_preferred) {
 1790                                 found = 1;
 1791                                 break;
 1792                         }
 1793                         if (ival >= verinfo->md_ver_minimum &&
 1794                             ival <= verinfo->md_ver_maximum &&
 1795                             ival > bestver) {
 1796                                 bestver = ival;
 1797                                 best = cp;
 1798                                 blen = clen;
 1799                         }
 1800                         break;
 1801                 default:
 1802                         break;
 1803                 }
 1804                 recptr += reclen + sizeof(int);
 1805         }
 1806         /*
 1807          * Finally check if KLD is in the place
 1808          */
 1809         if (found)
 1810                 result = linker_lookup_file(path, pathlen, cp, clen, &mattr);
 1811         else if (best)
 1812                 result = linker_lookup_file(path, pathlen, best, blen, &mattr);
 1813 
 1814         /*
 1815          * KLD is newer than hints file. What we should do now?
 1816          */
 1817         if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >))
 1818                 printf("warning: KLD '%s' is newer than the linker.hints"
 1819                     " file\n", result);
 1820 bad:
 1821         free(pathbuf, M_LINKER);
 1822         if (hints)
 1823                 free(hints, M_TEMP);
 1824         if (nd.ni_vp != NULL) {
 1825                 VOP_UNLOCK(nd.ni_vp, 0);
 1826                 vn_close(nd.ni_vp, FREAD, cred, td);
 1827                 VFS_UNLOCK_GIANT(vfslocked);
 1828         }
 1829         /*
 1830          * If nothing found or hints is absent - fallback to the old
 1831          * way by using "kldname[.ko]" as module name.
 1832          */
 1833         if (!found && !bestver && result == NULL)
 1834                 result = linker_lookup_file(path, pathlen, modname,
 1835                     modnamelen, NULL);
 1836         return (result);
 1837 }
 1838 
 1839 /*
 1840  * Lookup KLD which contains requested module in the all directories.
 1841  */
 1842 static char *
 1843 linker_search_module(const char *modname, int modnamelen,
 1844     struct mod_depend *verinfo)
 1845 {
 1846         char *cp, *ep, *result;
 1847 
 1848         /*
 1849          * traverse the linker path
 1850          */
 1851         for (cp = linker_path; *cp; cp = ep + 1) {
 1852                 /* find the end of this component */
 1853                 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++);
 1854                 result = linker_hints_lookup(cp, ep - cp, modname,
 1855                     modnamelen, verinfo);
 1856                 if (result != NULL)
 1857                         return (result);
 1858                 if (*ep == 0)
 1859                         break;
 1860         }
 1861         return (NULL);
 1862 }
 1863 
 1864 /*
 1865  * Search for module in all directories listed in the linker_path.
 1866  */
 1867 static char *
 1868 linker_search_kld(const char *name)
 1869 {
 1870         char *cp, *ep, *result;
 1871         int len;
 1872 
 1873         /* qualified at all? */
 1874         if (index(name, '/'))
 1875                 return (linker_strdup(name));
 1876 
 1877         /* traverse the linker path */
 1878         len = strlen(name);
 1879         for (ep = linker_path; *ep; ep++) {
 1880                 cp = ep;
 1881                 /* find the end of this component */
 1882                 for (; *ep != 0 && *ep != ';'; ep++);
 1883                 result = linker_lookup_file(cp, ep - cp, name, len, NULL);
 1884                 if (result != NULL)
 1885                         return (result);
 1886         }
 1887         return (NULL);
 1888 }
 1889 
 1890 static const char *
 1891 linker_basename(const char *path)
 1892 {
 1893         const char *filename;
 1894 
 1895         filename = rindex(path, '/');
 1896         if (filename == NULL)
 1897                 return path;
 1898         if (filename[1])
 1899                 filename++;
 1900         return (filename);
 1901 }
 1902 
 1903 #ifdef HWPMC_HOOKS
 1904 /*
 1905  * Inform hwpmc about the set of kernel modules currently loaded.
 1906  */
 1907 void *
 1908 linker_hwpmc_list_objects(void)
 1909 {
 1910         linker_file_t lf;
 1911         struct pmckern_map_in *kobase;
 1912         int i, nmappings;
 1913 
 1914         nmappings = 0;
 1915         KLD_LOCK();
 1916         TAILQ_FOREACH(lf, &linker_files, link)
 1917                 nmappings++;
 1918 
 1919         /* Allocate nmappings + 1 entries. */
 1920         kobase = malloc((nmappings + 1) * sizeof(struct pmckern_map_in),
 1921             M_LINKER, M_WAITOK | M_ZERO);
 1922         i = 0;
 1923         TAILQ_FOREACH(lf, &linker_files, link) {
 1924 
 1925                 /* Save the info for this linker file. */
 1926                 kobase[i].pm_file = lf->filename;
 1927                 kobase[i].pm_address = (uintptr_t)lf->address;
 1928                 i++;
 1929         }
 1930         KLD_UNLOCK();
 1931 
 1932         KASSERT(i > 0, ("linker_hpwmc_list_objects: no kernel objects?"));
 1933 
 1934         /* The last entry of the malloced area comprises of all zeros. */
 1935         KASSERT(kobase[i].pm_file == NULL,
 1936             ("linker_hwpmc_list_objects: last object not NULL"));
 1937 
 1938         return ((void *)kobase);
 1939 }
 1940 #endif
 1941 
 1942 /*
 1943  * Find a file which contains given module and load it, if "parent" is not
 1944  * NULL, register a reference to it.
 1945  */
 1946 static int
 1947 linker_load_module(const char *kldname, const char *modname,
 1948     struct linker_file *parent, struct mod_depend *verinfo,
 1949     struct linker_file **lfpp)
 1950 {
 1951         linker_file_t lfdep;
 1952         const char *filename;
 1953         char *pathname;
 1954         int error;
 1955 
 1956         KLD_LOCK_ASSERT();
 1957         if (modname == NULL) {
 1958                 /*
 1959                  * We have to load KLD
 1960                  */
 1961                 KASSERT(verinfo == NULL, ("linker_load_module: verinfo"
 1962                     " is not NULL"));
 1963                 pathname = linker_search_kld(kldname);
 1964         } else {
 1965                 if (modlist_lookup2(modname, verinfo) != NULL)
 1966                         return (EEXIST);
 1967                 if (kldname != NULL)
 1968                         pathname = linker_strdup(kldname);
 1969                 else if (rootvnode == NULL)
 1970                         pathname = NULL;
 1971                 else
 1972                         /*
 1973                          * Need to find a KLD with required module
 1974                          */
 1975                         pathname = linker_search_module(modname,
 1976                             strlen(modname), verinfo);
 1977         }
 1978         if (pathname == NULL)
 1979                 return (ENOENT);
 1980 
 1981         /*
 1982          * Can't load more than one file with the same basename XXX:
 1983          * Actually it should be possible to have multiple KLDs with
 1984          * the same basename but different path because they can
 1985          * provide different versions of the same modules.
 1986          */
 1987         filename = linker_basename(pathname);
 1988         if (linker_find_file_by_name(filename))
 1989                 error = EEXIST;
 1990         else do {
 1991                 error = linker_load_file(pathname, &lfdep);
 1992                 if (error)
 1993                         break;
 1994                 if (modname && verinfo &&
 1995                     modlist_lookup2(modname, verinfo) == NULL) {
 1996                         linker_file_unload(lfdep, LINKER_UNLOAD_FORCE);
 1997                         error = ENOENT;
 1998                         break;
 1999                 }
 2000                 if (parent) {
 2001                         error = linker_file_add_dependency(parent, lfdep);
 2002                         if (error)
 2003                                 break;
 2004                 }
 2005                 if (lfpp)
 2006                         *lfpp = lfdep;
 2007         } while (0);
 2008         free(pathname, M_LINKER);
 2009         return (error);
 2010 }
 2011 
 2012 /*
 2013  * This routine is responsible for finding dependencies of userland initiated
 2014  * kldload(2)'s of files.
 2015  */
 2016 int
 2017 linker_load_dependencies(linker_file_t lf)
 2018 {
 2019         linker_file_t lfdep;
 2020         struct mod_metadata **start, **stop, **mdp, **nmdp;
 2021         struct mod_metadata *mp, *nmp;
 2022         struct mod_depend *verinfo;
 2023         modlist_t mod;
 2024         const char *modname, *nmodname;
 2025         int ver, error = 0, count;
 2026 
 2027         /*
 2028          * All files are dependant on /kernel.
 2029          */
 2030         KLD_LOCK_ASSERT();
 2031         if (linker_kernel_file) {
 2032                 linker_kernel_file->refs++;
 2033                 error = linker_file_add_dependency(lf, linker_kernel_file);
 2034                 if (error)
 2035                         return (error);
 2036         }
 2037         if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop,
 2038             &count) != 0)
 2039                 return (0);
 2040         for (mdp = start; mdp < stop; mdp++) {
 2041                 mp = *mdp;
 2042                 if (mp->md_type != MDT_VERSION)
 2043                         continue;
 2044                 modname = mp->md_cval;
 2045                 ver = ((struct mod_version *)mp->md_data)->mv_version;
 2046                 mod = modlist_lookup(modname, ver);
 2047                 if (mod != NULL) {
 2048                         printf("interface %s.%d already present in the KLD"
 2049                             " '%s'!\n", modname, ver,
 2050                             mod->container->filename);
 2051                         return (EEXIST);
 2052                 }
 2053         }
 2054 
 2055         for (mdp = start; mdp < stop; mdp++) {
 2056                 mp = *mdp;
 2057                 if (mp->md_type != MDT_DEPEND)
 2058                         continue;
 2059                 modname = mp->md_cval;
 2060                 verinfo = mp->md_data;
 2061                 nmodname = NULL;
 2062                 for (nmdp = start; nmdp < stop; nmdp++) {
 2063                         nmp = *nmdp;
 2064                         if (nmp->md_type != MDT_VERSION)
 2065                                 continue;
 2066                         nmodname = nmp->md_cval;
 2067                         if (strcmp(modname, nmodname) == 0)
 2068                                 break;
 2069                 }
 2070                 if (nmdp < stop)/* early exit, it's a self reference */
 2071                         continue;
 2072                 mod = modlist_lookup2(modname, verinfo);
 2073                 if (mod) {      /* woohoo, it's loaded already */
 2074                         lfdep = mod->container;
 2075                         lfdep->refs++;
 2076                         error = linker_file_add_dependency(lf, lfdep);
 2077                         if (error)
 2078                                 break;
 2079                         continue;
 2080                 }
 2081                 error = linker_load_module(NULL, modname, lf, verinfo, NULL);
 2082                 if (error) {
 2083                         printf("KLD %s: depends on %s - not available or"
 2084                             " version mismatch\n", lf->filename, modname);
 2085                         break;
 2086                 }
 2087         }
 2088 
 2089         if (error)
 2090                 return (error);
 2091         linker_addmodules(lf, start, stop, 0);
 2092         return (error);
 2093 }
 2094 
 2095 static int
 2096 sysctl_kern_function_list_iterate(const char *name, void *opaque)
 2097 {
 2098         struct sysctl_req *req;
 2099 
 2100         req = opaque;
 2101         return (SYSCTL_OUT(req, name, strlen(name) + 1));
 2102 }
 2103 
 2104 /*
 2105  * Export a nul-separated, double-nul-terminated list of all function names
 2106  * in the kernel.
 2107  */
 2108 static int
 2109 sysctl_kern_function_list(SYSCTL_HANDLER_ARGS)
 2110 {
 2111         linker_file_t lf;
 2112         int error;
 2113 
 2114 #ifdef MAC
 2115         error = mac_kld_check_stat(req->td->td_ucred);
 2116         if (error)
 2117                 return (error);
 2118 #endif
 2119         error = sysctl_wire_old_buffer(req, 0);
 2120         if (error != 0)
 2121                 return (error);
 2122         KLD_LOCK();
 2123         TAILQ_FOREACH(lf, &linker_files, link) {
 2124                 error = LINKER_EACH_FUNCTION_NAME(lf,
 2125                     sysctl_kern_function_list_iterate, req);
 2126                 if (error) {
 2127                         KLD_UNLOCK();
 2128                         return (error);
 2129                 }
 2130         }
 2131         KLD_UNLOCK();
 2132         return (SYSCTL_OUT(req, "", 1));
 2133 }
 2134 
 2135 SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLFLAG_RD,
 2136     NULL, 0, sysctl_kern_function_list, "", "kernel function list");

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